I am using v3.3.8.1 DEV R1 and often (not everytime, but often) when I load my single player world the carpenters blocks revert to plain block without any "block in them". After I update the block (for example rotating it with Carpenters Hammer) it turns back to what it should be.

It "reverts" only few blocks in row, so it is not randomly. The blocks are in one chunk, not crossing border. They were "painted" with normal vanilla glass and marble from Chisel mod.

edit: Also I dont remember this happening with stable v3.3.8

Forge 1614
MC 1.7.10